hsukaria

Manifold injection was also called Throttle Body Injection (TBI). It was an improvement over a carburator because of improved fuel control and does not use a venturi. A venturi causes a vacuum in the intake manifold for fuel suction, but also causes power loss because it lowers the cylinder pressure.

Port Fuel Injection injects fuel just upstream of the intake valves. It is an improvement in performance and emissions over throttle body injection. But still suffers from fuel puddles accumulating on the back of the intake valve.

Direct fuel injection started out in diesels, but is now also used in the latest gasoline engines. It provides the best fuel control, and power. The biggest benefit of gasoline direct injection is that when the fuel is injected at the compression stroke, it actaully causes a rapid cool down of the compressed air, allowing for reduced pumping losses by allowing the air to cool down and condense right before combustion.

As mentioned before, the fuel injection in model engines would be the throttle body (or manifold) injection. If done properly, besides helping with fuel control, it can help with increasing power by eliminating the carb venturi.

earlwb

Actually they did that with the glow engines already. The combat, speed and hi-perf FF engines used bladders that you inflate with fuel. The bladders developed a lot of pressure too. The intakes on the engines then used a large intake hole with no venturi, since they don't draw fuel the intake can be made larger, and the needle valve assembly usually wound up being a 1/2 length/size unit on one side and it sprayed the fuel directly into the intake with no obstructions inside.
The pylon racers did it to some extent as well (at least until idle rules in some classes were implemented).

OS went all the way and marketed a real fuel injected 4 stroke engine for a while, with a real fuel pump, fuel injector and a ECU unit.

hsukaria

I've been told about the OS fuel injection before. I bet it wasn't cheap, but OS is never cheap.

flyingagin

I have have looked but have not seen or heard anymore than what I have seen here. Not interested in owning one just curious. I like motors. Any I only have a rubber band motor budget
pics? links? data?

Hobbsy

My Feedback: (102)

Test post

Rudolph Hart

I'm sure happy i read all these posts it's a lively conversation.I'm going to start off running a vp20 pump and exhaust pressure.

earlwb

It is pretty awesome in that the ECU controls the engine, so there are no needle valves to adjust. If it wasn't for the cost, it might have revolutionized the glow engine market especially with beginners.

OS advertisement for them http://www.os-engines.co.jp/english/...0sfi/index.htm

OS had a .91, 1.60 and a 2.00 fuel injected engine.
Tower Hobbies still has some parts even.
http://www3.towerhobbies.com/cgi-bin...=OSMG0941&P=OW



OS had a 2 stroke 1.60 with FI:




OS FS091FI in use. it is not mine though. Sorry.

w8ye

My Feedback: (16)

Life wasn't so simple as fly out of the box with the OS FI engines as you had to follow a procedure to establish the limits of the fuel mixture algorithm about as often as you would need to adjust the needle valve on a regular carb engine. You would get along with the same limits all summer but in the fall as the weather started getting a little cooler, you would have to set the limits up again.

flyingagin

WOW those are some awesome engines> Beautiful
OH well rubber band motors for me.
I will stay with my Saito .65 and ST, and OS that I have.

Kostas1

But it was a really nice and innovative idea anyway, right;

hsukaria

Those fuel injected engines are awesome. But I'm sure only the professional competition guys would spend that kind of money (or you are crazy about engines).

I'm just happy I was able to replace a piston ring on one of my cheaper 2-strokes last weekend. I will bench run it soon to break it in. Simple pleasures.

Hobbsy

My Feedback: (102)

As you can see my pictures posted some time after I actually posted them. The YS 1.15 finally has the regulator where it should have been all along. The 1.70 has the fuel injection pump on the intake pushrod and the mixture is controlled by the carb barrel

hsukaria

The picture on the right has a servo pigtail wire. Does that connect to a receiver and eliminates the throttle servo? The FI also controls the throttle?

Hobbsy

My Feedback: (102)

I suspect that would be a throttle position sensor to make the fuel injection more accurate, that's just a guess though.

Hobbsy

My Feedback: (102)

PS. I just did some more digging and that engine is a new 1.75 that is, "comming soon" there is no explanation for the wire.

gkamysz

My Feedback: (19)

The wire in the YS DZ-1.70 CDI photo is for the spark trigger. I just got a FS-91S-FI. I'm looking forward to trying it.

hsukaria

Oh, so those pictures are not off your workbench? I was marveling at how clean your workbench is compared to mine.

hsukaria

FI for a spark engine would be great because you already have to have the electronic ignition module and battery anyway. So you add an extra couple of wires for the injection system and you're all set. That might be feasible from a cost/complexity point of view. Plus the FI would incorporate the function of fuel pumping and pressure regulation!!!

Nikolas K

OS electronic fuel injection is a nice concept, but judging from the instructions manual, the tuning of the injection system is something complicated and aimed for experienced modellers. However, I believe that if the simple glow carb was inadequate, electronic fuel injection would have taken its place (just like in automobile engines). Talking about fuel injection however, what makes 4 stroke YS engines system a "fuel injection" system?

JariV

My member number can be released for someone else. I sold my only Saito engine.

hsukaria

Don't you know that the Saito Club is like the mafia, once you join, you can never quit.

triumphman49

My Feedback: (149)

Hi JariV, What other types of engines do you have?

T-man49
Club Saito #723

NM2K

My Feedback: (14)

He'll be back. Saito engines are habit forming. (smile)


Ed Cregger

hsukaria

I ran my Saito 1.8 earlier today. I'm still in Cloud 9.[8D]

KenD

My Feedback: (65)

What is the requirements to become a Club Saito member?